Flow cytometry has become the primary tool for the isolation of cell populations according to specific parameters, and is therefore employed by an ever-growing number of biomedical scientists. However, this method is technologically complex and the equipment expensive, necessitating shared instrumentation amongst groups of users to facilitate expert use and availability of this vital and versatile instrument. The Columbia Center for Translational Immunology (CCTI) Flow Core has become the go-to destination for flow sorting by biomedical researchers at Columbia University Medical Center (CUMC) because of the available of high-quality operator assisted sorts. As a result of the growth of the CCTI (7 additional PIs in 3 years) and the increased demand from non-CCTI users, the flow sorter is now substantially oversubscribed. The 6 Major Users require human cell sorting, often same-day, for their NIH-funded studies, which include, mapping T cell populations in tissues (Farber), investigating B cell populations in human transplant (Zorn), clinical studies (Clynes), investigations of humanized mouse models of dendritic cells, cancer, autoimmunity and transplantation (Liu, Sykes, Yang), and identification of epigenetic changes in autoimmune T cells (Clynes). Inflammation is at the heart of many human diseases and the eleven Minor User projects vary from transplantation, human skin stem cells and autoimmune alopecia areata, to atherosclerosis, to neurodegenerative disease. The growth in human immunology at CUMC and the need for on-call sorting, in particular, mandates a second CCTI sorter. We have taken this opportunity to convince the Department of Medicine to provide dedicated space for enhanced BSL2+ Biosafety for human cell sorting. Due to the intensive usage of the current CCTI BD Influx and the benefit of higher level of biosafety containment, and with solid institutional commitment of the Department of Medicine (BSL2+ sorter room renovation and salary support for a dedicated operator) we request NIH funding for the purchase of an Influx sorter from BD Biosciences.